Direct-current apparatus.



C. W. GIRVIN.

DIRECT CURRENT APPARATUS. APPLICATION FILED MAY 12. 1913.

B SHEETS-SHEET I- Patented May 1, 1917.

C. W. GlRVlN. DIRECT CURRENT APPARATUS.

' APPLICATION FILED MAY 12, 1913. 1,224,160.

Patented May 1, 1917.

BsHEETs-sHEET 2.

WI TIIESSES INVENTOI? C. W. GIRVIN.

DIRECT CURRENT APPARATUS.

I APPLICATION FILED MAY 12, 1913. Patented May 1,

8 SHEETS-SHEET 3- WITNESSES [NYE/{TOR C. W. GIRVIN.

DIRECT CURR ENT APPARATUS. APPLICATION FILED MAY I2. 1913- 1,224,160. Patented May1,1917.

8 8HEETSSHEET 4- I .Q 672 Z 5 c' C d T 7' V //f 5 WITNESSES.

. I "(IE/170R I t% I I C. W. GIRVlN.

DIRECT CURRENT APPARATUS.

APPLICATION FILED MAY 12, I913.

Patented Mayl, 1917.

8 SHEETSSHEET 6.

II B:

a; ll Q o n i a k 0) CIT.

b X m L "WEN-TOR C. W. GIRVIN.

DIRECT CURRENT APPARATUS.

APPLICATION FlLED' MAY 12, 1913.

Patented May 1, 1917.

8 SHEETS-SHEET I.

B m MED magmas??? Q vk Patented May 1, 1917 a sueeTs-asnsn s c. w. emvm. DIRECT CURRENT APPARATUS.

APPLICATION FILED MAY l2. I913.

WITNESSES I UNITED STATES PATENT OFFICE.

CHARLES W. GIRVIN, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO GIRVIN ELEC- TRICAL DEVELOPMENT COMPANY, LIMITED, OF HONOLULU, TERRITORY OF HAWAII, A CORPORATION OF THE TERRITORY OF HAWAII.

DIRECT-CURRENT APPARATUS.

Application filed May 12, 1913.

To all whom it may come m:

Be it known that I, CHARLES V. GIRVlN,

certain new and useful Improvements in Direct-Current Apparatus, of which the following is a specification.

My invention relates to improvements in direct current apparatus.

The present invention, while adapted for general use, is designed more particularly for use in connection with high tension mechanism, being specific embodiments of the commutator forming a part of the invention disclosed in my companion application, filed March 11, 1812, Serial No. 683,065, said application having as its subject matter mechanism for generating'or employing direct current of high potential.

The commutator may be employed as a part of a mechanism for generating current or of apparatus acting as a motor and employing direct current. For explaining the structure and operation, I'am assuming the structure to be a part of a current generating mechanism.

The commutator is designed more particularly for use in connection with apparatus employing a stationary armature and a rotating field magnet, the commutator traveling in synchronism with the field magnet,-

the armature being made up of a plurality of coil units, each unit having its terminals leading to the commutator, the terminals being preferably in the form of brushes adapted to relatively traverse the commutator, the coil units being preferably of the open-circuit type, the circuitbeing closed through the commutator in such manner that the coil units remain constantly in circuit and a pre-determined number thereof are maintained constantly in series relationship. This general idea forms the subject matter of the companion application referred to, and the specific embodiments thereof, other than the commutator, are not presented herein except in conventional form.

The present invention has for its objects:

1. To provide a structure of this 'character in which the difference in potential between rows of brushes may be readily adjusted so as to be below the point where flashing will take place.

Specification of Letters Patent.

Patented May 1, 191

Serial No. 767,060.

2. To provide a structure of this character embodying segments arranged in cir-' cumferential rows and also in approximate rows extending longitudinally of the commutator. and preferably having the terminal brushes of a coil unit adapted to traverse adjacent circumferential rows, the terminal,

segments being connected with segments of other circumferential rows to provide for rectifying the alternating current at proper times to produce. the direct current.

3. To provide a structure of this character in which the connections are simple and in which maximum insulation may be provided to insure operation under high potentials.

4. To provide a structure which may be in the form of sections readily assembled on the supporting shaft, and which may be in the form of units capable of being placed in or taken out of position with ease and rapidity to enable repairs to be quickly made when necessary by the substitution of one section for another.

5. To provide a structure of this character of minimum size for maximum output. 6. To provide a structure of this character in which Various methods of assisting commutation of the currents in the coil units may be used.

Other and further objects are to provide rable in construction.

To these and other ends, the nature of which will be readily understood as the invention is hereinafter disclosed, my invention consists in the improved construction simple and eflicient in operation, and du- =and combination of parts hereinafter fully described, illustrated in the accompanying drawings, and more particularly polnted out in the appended claims.

In the accompanying drawings, in which similar reference characters indicate similar a construction and arrangement which .is

F ig. is a diagrammatic View illustrating in which the connections maybe provided to amist in commutation.

Fig.12 is an end elevation, partly in section, of one way in which the commutator may be constructed.

Fig. 13 is a side elevation, partly in secti0n,'of the structure shown in Fig. 12.

Figs. 14, 15 and 16 are fragmentary sectional views illustrating other ways of mounting the segments.

Fig. .17 is a fragmentarydeveloped diagrammatic View showing an arrangement of segments in which the gaps between segments which cooperate with the brushes of coil unit during the short-circuiting action are enlarged to decrease liability of the formation of an arc across these gaps when the'short-circuit is broken.

Fig. 18 is a similar view showing a different arrangement for accomplishing the same purpose, the segments being of reduced size and the gaps being provided by the use of blank segments.

Fig. 19 is a similar view showing a combination of the arrangements of Figs. 17

' and 18.

Fig. 20 is a view of aportion of Fig. 18 showing blank segments connected by resistance conductors.

As heretofore pointed out, the commutator herein disclosed is adapted for use in connection with the mechanism of the companion application heretofore referred to, and while adapted for general use is, designed more particularly for the type of apparatus of said application. The following description will'be made in connection with such preferred mechanism, and to enable a clearer understanding to be had, a brief description of said mechanism will'be giYen.

The mechanism 1s similar in general construction to a stationary-armature polyphase alternating current generator or synchronous motor, with the coil unit's, however, retained in individual open-circuit relation, the con-.

nections between coil-units being provided through the commutator, this connection .being formed. by the use of commutator segmentsconnected together in particular manner, the coil units having their terminals in the form of brushes adapted to relatively traverse the segments. The armature being stationary, as are the brushes, the commutator is rotated in synchronism (not necessarily at the same angular speed) with the rotating field magnet, this arrangement enabling the commutator to be carried by the shaft of the field magnet rotor or separate therefrom as the exigencies of use may demand.

The terminal brushes of each coil unit operate in connection with separate segments insulated from each other, and one of. the features of said companion application relates to the arrangements of connections between terminal brush segments of adjacent coil units, the purpose being to maintain a predetermined number of the coil-units constantly in series relationship through the commutator acting invidually on each unit, the commutator also maintaining all of said units in a constantly closed circuit.

In Fig. 1 I illustrate diagrammatically a simple form in which this idea may be carried out In this view the field poles are indicated at M, the windings of the armature being indicated at a, b, 0, etc. As indicated in the companion application, the coil units may be made up of one or more windings or conductors connected together in any of a desired number of ways, each coil unit, however, having its two terminals connected to independent brushes. In the present drawings, for the purpose of clearness, a coil unit is indicated by a single line. In said Fig. 1 I have shown four rows'of brushes, these extending longitudinally. of

the commutator, each row being assumed to provide the terminals for four coil units, the brushes of a coil unit being located side by side. This showing is simply illustrative, since the number of brushes in a row may be as the exigencies of construction may demand, as may be the number of rows. The four rows, however, will also illustrate successive positions of a single row of brushes and thereby indicate the manner in which the connections between terminal brushes of adjacent coil units will be provided when reversal in E. M. F. of the coil units takes place.

As will be readily understood, the showing of four coil units within a pole pitch is simply an example, the number of units being as may be desired, it being preferred to employ at least a suflicient number to producea substantially continuous current; while the brushes of these units may be arranged in more than a single row, they are assumed to be connected in series through the commutator connections.

' For the purpose of indicating the brushes, I'have indicated those for coil unit a as a,

. a those forcoil unit I) as 6, 6 those for coil unit 0 as 0 etc. The end brushes in- =12 brushes of'the row, on being the Positive and the. other the negative terminal of that row.

The commutator is provided with a plurality of rows of segments, the segments being insulated from each other as required, the. rows being preferably arranged both longitudinally and circumferentially, this forming the simplest arrangement of these segments. The connections between the terminal brushes of adjacent units is provided .by connecting segments which pass into contact with the brushes, and these connections are indicated in Fig. 1 by the dotted lines C.

- For the purpose of producing the result .in said preferred machine, the connections vary in correspondence with the reversalsin'the E. M. F.s of the coil units. For instance, in Figs. 6 to 10 I have shown the arrangement of .connections for four coil units in which the reversals of the E. M. F.s occur in regular order, the units being assumed to be those indicated as a, b, c, d, in Fig. 1. Fig. 6 indicates the connections When the direction of E. M. F. is similar in each unit, the connections providing-for a maintenance of the units in series. Fig. 7 illustrates the connections when the direction of E. M. F. in coil unit a hasreversed, these connections also maintaining the units in series and in circuit. Figs. 8, 9, and 10 illustrate the connections at the respective times when the units 6, 0, and d have'had their E. M. F.s successively reversed, these views indicating the maintenance of the series relationship and closed circuit of the coil units.

The arrangement, while of the open-coil type in construction, :is of the closed-coil type in operation, in this respect operating similarly to commutating machines in that the bridging of segments due to the travel of the commutator while" the coil units are undergoing commutation, causes a short-circuiting action, and this can be taken care of by the use of resistances as in Fig. 11,'or by compensating windings on the rotor, or by commu'tating' poles as in Fig. 3 (.these latter being indicated at GP) or by a combination of these methods, each being well known in the-art; or other arrangements for assisting commutation may be employed, the

particular form depending upon the individual preferences or the exigencies of use,

or such assisting means may be omitted.

The general arrangement of the mechanism as an entirety is not specifically set forth herein, as it forms the subjectmatter of. the said companion application, the present application pertaining more particularly to the specific'structure and arrangement of the commutator itself.

In the-form shown in Fig. 1, the segments,

indicated at S, areshown as arranged in rows extending peripherally or circumferentially about the commutator, it being understood that the segments are insulated from each other in this direction. This is a common feature in each of the forms disclosed, the commutator being rotatable. This arrangement provides for a substantially fixed path for each brush during the rotation of the commutator, each circumferential row having its segments passing successively under its individual brushes. In the preferred form, and in each of the forms illustrated, no two segments of the same peripheral row are connected electrically. However, I do not limit myself to this con: struction, since it is possible that under certain circumstances certain adjacent segments may be connected electrically. to provide the equivalent of a segment of greater length, or it may be possible to place the brushes of both terminals of a unit so as to operate on the same row (peripheral) of segments, this latter, however, requiring a rather intricate wiring of the commutator and while providing the same'general results this would be obtained in a somewhat disadvantageous manner. It is to. be understood that such arrangement falls within the spirit and scope of the invention.

As shown, the segments are also arranged in rows longitudinally of the commutator, the segments being spaced apart in general with the necessary electrical connections be- This particular arrangement of the seg- I ments longitudinally, however, is not arbitrary, since it may be desirable to have adjacent brushes offset from each other and in such event, the segments may also be offset, especially where the offsetting of the brushes is not sufiicient to cause adjacent brushes to properly position on an adjacent longitudinal row of segments. This latter will be more clearly understood by referring to Fig.- 2, in which the brush (1. is shown as in advanced relation to the brushes aand b, the advancement being to the second 10ngitudinal row; obviously the advancement might be to the succeeding-row, or to such a position where it would bridge adjacent circumferential segments of Fig. 2, whereupon a shifting of the row of segments circumferentially so as to cause the brush to be properly positioned on its segment would cause the segments to be offset with respect to each other. I e

In each instance the general order of connections between segments will be preserved, it being readily understood that the connections shown in Fig. 2 are the equivalent of those shown in Fig. 1, the general operation being similar in each instance. As will be readily understood the general arrangement'shown in Fig. 1 is of greater ease in manufacture and is therefore a preferable one.

Such changes in the particular arrangements of segments will not affect the generalinvention herein disclosed, and it is to be understood that they fall within the spirit and scope of the invention.

The number of segments contained in a longitudinal row is preferably determined by the number of coil units which it may be desired to operate on that row. As heretofore pointed out, two brushes in each longitudinal roware employed in connection with each unit, and in addition, two additional segments are provided for the terminal brushes of the row; or where it is desired to provide intermediate terminals to be used for tapping the armature', additional segments may be provided atthe desired points. In Fig. 1 I have shown the brushes of four coil units per row, thus providing for 10 segments longitudinally of the commutator;

. additional coil units would add the segments in pairs and intermediate terminals would add a segment for each of such terminals' The number of segments contained in the peripheral or circumferential rows may vary to meet different conditions, but it is preferred that the minimum number correspond to the number of coil units in a pole pitch .of the armature times the number, of main field poles, where'the angular speed of the rotor and of the commutator is in exact correspondence; where the angular speed of the commutator is proportionately greater or less than that fof the rotor, the minimum number of segments would be respectively less or greater in the same ratio. In view of the fact that, where highvoltages are to be dealt with per coil unit or between rows of brushes, the question of preventing flashing becomes important, and it is preferable to increase the number of segments in the circumferential rows, thereby increasing the number of gaps in series between any two points oflarge difference of potential.

As shown diagrammatically in Figs. 1 and 2, and 6 to 10 inclusive, the connections between segments is longitudinally of the commutator only, there being no connections between segments of a circumferential row, the

connections being between terminal'brushes of coilunits'the pairs ofbrushes of which are adjacent each other. For instance, in

there being no connection between the segments on which the brushes a and a rest. From this it will be seen that the only connection between the terminal brushes of a coil unit is through the coil unititself, each of the brushes of that coil unit, however, being connected with terminal brushes of other coil units or of the terminals T or T through the connections C. This form of construction is maintained throughout the commutator, the changes required during the short-circuiting operation by the reversal in E. M; F. in the coil unit being provided by changing the connections, these changes being indicated in Figs. 6 to 10 inclusive which show the connections of succeeding longitudinal rows of se ments over which the brushes of four coi units (in one row) are adapted to haverelative movement, these connections being shown in Fig. 1 beginning with the 5th longitudinal row of segments from the left of 'said figure.

. This change in connections is made at the instant when the E. M. F. in the coil unit is undergoing reversal and since' this reversal takes place in connection with each pole of the field magnet and at equal time intervals,

; it will be understood that the relative-arrangement of connections of a longitudinal has this reversal in E. M. F. in a longitudi-.

nalrow, each unit having an independent row, it will be understood that the segments in a circumferential 'row between these reversal rows sim ly maintain the connections provided by such reversal rows.

, As a result, the terminal brushes of a unit are subjected to the short-circuiting action and the resulting short-circuit current only when bridging the gaps between segments of changed connections, the brushes being free from such super-imposed current during the remaining movements of the commutator, so

that such brushes are only intermittently subjected to this current and this during a relatively short period of time, thus tending to reduce liability'of heating and wear of the brushes. And;under these conditions, it will be readily understood that. any sparkmg at the brushes'whi'ch might be present would occur only at these timed intervals.

In'Figs. 17 to'20 inclusive I have shown arrangements of segments which will decrease the liability of the formation of an arc in the gaps between segments, the bridging of which takes place during the short-4 circuiting of a coil unit. For the purpose of indicating this action I have, in Fig. 17, designated certain segments with reference numerals from 2 to 33 inclusive.

In Fig. 17 the brushes are shown in the position in which coil unit 6 is short-circuited, its brushes 1) and bridging two ment 20, through brush 0 to segment 19 and then to segment 16. As the travel of the commutator causes the brushes to leave the row containing the segments 3, 6, 9, etc., assuming the commutator travel to be in the direction of-the arrow in said figure, these short-circuit paths are each broken at two points, and by increasing the widthsof the gaps at these points, the resistance of the short-circuit is materially increased, thus assisting commutation and at the same time reducing the liability to form an aroacross the gaps. Obviously, the gaps between the remaining segments may be of the normal size. Vhile I have shown all of these gaps as enlarged, it will be'obvious that such enlargement may be had only with respect to two of the gaps (one in connection with each path) these being those between segments 12 and 13 and between segments 16.

and 17 respectively.

These enlarged gaps for coil unit a, in Fig: 17 are those shown between the seg ments 2 and 3, 5 and (i. 8 and 9, and 11 and 12, these gaps including that bridged by the terminal brush T which would form part of one of the short-circuit paths when the coil unit 0. is undergoing reversal in E. M. F Similarly the gaps between the segments 13 and 14, 20 and 21, 23 and 21 and 26 and 27 would'provide this function in connection with coil unit 0.

In Fig. 18' I have shown an equivalent arrangement, the segments in this figure being, for purposes of illustration, substantially halt' the length of those shown in Fig.

17. In thistype, the pairs of .segments corresponding to a single segment of Fig. 17 have individual connections so as to produce the same result ,as in Fig. 17. However, instead ofenlarging the gaps, as in Fig. 17, I provide what may be termed blank segments within the circumferential rows at the points corresponding to the enlargcd gaps of Fig. 17, these blank segments being formed by omitting the. usual connections between the segmcnts at such points as would cause the blank segments to lake the place of the enlarged gaps in Fig. 17.

In Fig. 19 I have shown a combination of the arrangements of Figs. 17 and 18, the

blank segments occupying the positions of the enlarged gaps in Fig. 17.

In Fig. 20 I have shown an alternative ar- 'angement by connecting blank segments with a resistance conductor, this arrangement permitting the discharge of the inductive E. M. F. due to breaking the short-circuit current in the coil unit.

The commutator may be constructed in any desired manner, Figs. 12 to 16, showing various ways .in which this may be pro.

vided, the general arrangement being along those of well known lines employing a plurality of rings arranged to. embrace segments, these rings being indicated at R and having configurations complemental to those of the segments which they are adapted to retain in position, being along the lines of what is generally known as the V ring con struction of ordinary commutators. In

Fig. 13 I have shown the rings which emtial row as being connected together, thus enabling the commutator to be built in sections, the connections leading from the segments inwardly and passing within the retaining rings R. In Fig. 1-1 I-have shown a modified form in which two circumferential rows of segments are clamped together as a unit, the connections leading inwardly from the segments. In Fig. 15 I have shown the connections between segments as being outside the retaining rings, while Fig. 16 indicates the segments as joined together to form a single segment. The structures of Figs. 15 and 16 could obviously be employed only where adjacent segments are connected together. as for instance in Fig. 6.

Obviously other ways in which the segments may be mounted can be employed, the particular forms shown in Figs. 13 to 16 providing for a ready assemblage or taking apart. and also for enabling the formation of the commutator in sections, each section being readily removable as a unit, the form of mounting and the general arrangement of segments being such that in case of necessity asection may be readily removed and replaced by a corresponding section. making the time when the machine is out of service relatively small, the substitution of one section for another being made with rapidity and without requiring disengagement of any but supporting connections.

Vhile I have herein shown and described several ways in'which my invention may be carried into eiiect, it will be readily understood that changes and modifications therein may be required or desired to meet individual preferences or the exigencies of use,

Having thus described my invention, what I claim as new is:

1. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cotiperate with said brushes to place said units constantly in. a closed series circuit, said commutator having individual segments connected in pairs with each coil unit adapted to intermittently connect' the pairs through contact of its brushes with a segment of each of such pairs, and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator.

2. Indirect current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having segments connected in pairs and rendered active intermittently by contact with the terminal brushes of a coil unit, said unit forming the connection between the pairs and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator.

3. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having segments connected in pairs and rendered active intermittently by individually contacting with the terminal brushes of a coil unit, said unit'forming the connection between the pairs and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator.

4. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with .said brushes to place said units constantly in a closed series circuit, said commutator having individual segmentsarranged in circumferential rows, the

. segments of one rowv being permanently connected with segments of other rows, the

connections providing pairs of segments, a coil unit adaptedto intermittently connect segments of different pairs through contact of its brushes therewith and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the communtator, the

segments of a circumferential row being positioned in the same assemblage unit.

5. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments of other rows, the connections providing pairs of segments, a coil unit adapted to intermittently connect segments e f-different pairs through contact of its brushes therewith, succeeding segments of the row having similar-pair connections. and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator, the segments of a circumferential row being positioned in the same assemblage unit. I

6. In direct current machines, an arma ture having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, saidcommutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments'of other rows, the connections providing pairs of segments, a coil unit adapted to intermittently connect segments of diflerent pairs through contact of its brushes therewith, succeeding segments of the row having dissimilar pair connections and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator, the segments of a circumferential row being positioned in the same assemblage unit;

7. In direct currentmachines, an armature having a plurality of, open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit,

" said commutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments of other rows, the connections providing pairs of segments, a coil unit adapted to intermittently connect segments of different pairs throu h contact of units being positioned successively in the direction of the length of the commutator, the segments of a circumferential row being positioned in the'same assemblage unit.

8. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having individual segments arranged in. circumferentialrows, the segments of one ,row, being permanently con-. nected with segments of other rows,'the connections providing pairs of segments, a coil unit adapted to intermittently connect segments of different pairs through contact of its brushes therewith, succeeding segments of the row having dissimilar pair connections, dissimilarly connected pairs being at equally-spaced points in the row and supporting means for the segments adapted to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator,

the segments of a circumferential row being positioned in the same assemblage unit.

9. In direct current machines. an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments of other rows, the connections providing pairs of segments, a coil unit adapted to intermittently connect segments of differentpairs through contact of its brushes therewith, succeeding segments of the row having dissimilar pair connections, dissimilarly connected pairs being at spaced points in the row, said points being positioned to cause the pairs to be rendered active in correspondence with the reversal of E. M. F. in the coil unit and supporting means for the segments adapted to form assemblage unit's therewith, the assemblage units being positioned successively in the direction of length of the commutator, the segments of a circumferential row being positioned in the same assemblage unit.

10. In direct current machines, an armature having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments of other rows, the connections providing pairs of segments, a coil unit adaptedfto intermittently connect segments of different pairs through contact of its brushes therewith, a segment of one row having its pair connection with a segment of an adjacent row and supporting means for the segments adapted; to form assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator, the segments of a circumferential row being positioned in the same assemblage unit.

11. In direct current machines, an arma ture having a plurality of open-circuit coilunits, brushes forming terminals for said coil units, a rotatable commutator adapted to cooperate with said brushes to place said units constantly in a closed series circuit, said commutator having individual segments arranged in circumferential rows, the segments of one row being permanently connected with segments of other rows, the connections providing pairs of segments, a coil unit adapted to intermittently connect segments of different pairs through contact of its brushes therewith, a segment of one row having its pair connection with a segment of an adjacent row, the succeeding segment of that row having connection with asegment of a different row and supporting means for the segments adapted to form'assemblage units therewith, the assemblage units being positioned successively in the direction of length of the commutator, the segments of a circumferential row being positioned in the same assemblage unit. 12. In direct current apparatus having sources of alternating E. M. F., 'a rotatable commutator therefor having segments lo cated in approximate alinement longitudinally of the commutator, a plurality of segments individually cooperating intermit' tently with one of said sources to maintain said source constantly in Ci1C l1it,"Said segments being active as currentcarriers solely during such periods of cooperation, said commutator having a line of segments including both active and inactive segments. 13. In direct current apparatus having sources of alternating E. M. F., a rotatable commutator therefor having a plurality of segments cooperating intermittently with one of said sources to maintain said source constantly in circuit, said segments being active as current carriers solely during such periods of cooperation, a lineof segments extending longitudinally of the commutator having both active and inactive segments.

1%. In direct current machines having sources of alternating E. M. F., a rotatable commutator having a plurality of segments approximately alined longitudinally of the commutator and individually cooperating intermittently with said sources to maintain said sources constantly in circuit, said segments being connected to provide a series relationship between predetermined sources when predetermined segments become active, said alined segments including active and inactive segments.

15. In direct current machines havingsources'of alternating E. M. F'., a rotatable commutator having a plurality of segments approximately alined longitudinally of the commutator and individually cooperating intermittently with said sources to'maintam said sources constantly in circuit, said seg- .ments being connected to provide a series relationship between predetermined sources when predetermined segments become active, said predetermined segments being rendered active concurrently, said alined segments including active and inactive segments. g

16. In direct current machines having sources of alternating E. M. F., a rotatable commutator having a plurality of segments approximately alined longitudinally of the commutator and individually cooperating intermittently with said sources to maintain said source's constantly in circuit, said segments being connected to provide a series relationship between predetermined sources I when predetermined segments become. active,

said predetermined segments being. rendered active concurrently, successive segments circumferentially of the commutator becoming active in successive order, said alined segments including active and inactive segments.

17 In direct current machines having sources of alternating E. M.'F., a rotatable commutator having'a plurality of segments approximately alined longitudinally of the commutator and individually coiiperating intermittently with said sources to maintain said sources" constantly n circuit, sald segments being connected to provide a series relationship between predetermined sources when predetermined segments become active,

said predetermined segments being rendered active concurrently, successive segments circumferentially of the commutator becoming active in successive order, said connections 'between segments being varied at points where activity of the segments is concurrent with F. reversal, said alined segments including active and inactive segments.

18.111 direct current machines having sources of alternating F.,' a rotatable commutator having a plurality of segments arranged in circumferential rows andsindividually cooperating intermittently with such sources to maintain said sources constantly in circuit and provide a continuous current through said sources during the activity of segments, said row segments be ing spaced apart with the spacing increased between successive segments active during E. M. F. reversal 19. In direct current machines having sources of alternating E. M. 'F., a rotatable commutator having a plurality of segments arranged in circumferential rows and individually cooperating intermittently with such sources to maintain said sources concurrent through said sources during activity of segments, said row segments being spaced apart with the spacing increased between successive segments active during E. M F. reversal, blank segments within said spaces of increased width and a resistance element connecting blank segments on which the brushes of a coil unit rest.

In testimony whereof I affixmy signature in presence of two witnesses.

v CHARLES W. GIRVIN.

Witnesses: I

A. M. THIESON, HORACE G. Snrrz. 

